Who had the most impact on Callen's identity journey in NCIS: Los Angeles?

The Callen Identity
NCIS: Los Angeles (2009)
NCIS
TV
The Callen Identity poll options
The Callen Identity
NCIS: Los Angeles (2009)
NCIS
- Hetty Lange
- Arkady Kolcheck
- Sam Hanna
- Joelle Taylor